Effect of Alloying Elements (Mo and Al) on Biomaterials Ti-Ta Shape Memory Alloys

Titanium-Tantalum shape memory materials have widespread potential in biomedical applications. In this research, the alloy of Ti-Ta has been prepared using powder metallurgy techniques with a fixed percentage of Ta (30 at%). Alloying elements, specifically Mo and Al, were added in various compositions (1 at%, 2 at%, and 3%) to the master alloy (70% Ti - 30% Ta) to enhance corrosion resistance and mechanical properties. The assessment methods included X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM), Differential Scanning Calorimetry (DSC), Vickers hardness measurements, porosity percentage analysis, and corrosion rate evaluations in different solutions (artificial saliva, Ringer solution, and blood plasma). Results from XRD and microstructural analyses showed that all samples comprised two phases (β-phase and α-phase) at room temperature, indicating that the presence of Mo and Al did not alter the phases. The transformation temperature exhibited a decreasing trend with increasing Mo content, while it increased with higher Al percentages. Furthermore, the addition of Mo and Al generally reduced hardness, except for the 3% Mo sample which exhibited higher hardness compared to the master sample. Notably, the samples with 3% Mo showed improved corrosion resistance in all solutions analyzed, while Al demonstrated good corrosion resistance particularly in artificial saliva and blood plasma.